| /* |
| * Copyright 2018 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #ifndef SkMaskFilterBase_DEFINED |
| #define SkMaskFilterBase_DEFINED |
| |
| #include "SkBlurTypes.h" |
| #include "SkFlattenable.h" |
| #include "SkMask.h" |
| #include "SkMaskFilter.h" |
| #include "SkPaint.h" |
| #include "SkStrokeRec.h" |
| |
| class GrClip; |
| class GrContext; |
| struct GrFPArgs; |
| class GrRenderTargetContext; |
| class GrPaint; |
| class GrFragmentProcessor; |
| class GrRenderTarget; |
| class GrResourceProvider; |
| class GrTexture; |
| class GrTextureProxy; |
| class SkBitmap; |
| class SkBlitter; |
| class SkCachedData; |
| class SkMatrix; |
| class SkPath; |
| class SkRasterClip; |
| class SkRRect; |
| |
| class SkMaskFilterBase : public SkMaskFilter { |
| public: |
| /** Returns the format of the resulting mask that this subclass will return |
| when its filterMask() method is called. |
| */ |
| virtual SkMask::Format getFormat() const = 0; |
| |
| /** Create a new mask by filter the src mask. |
| If src.fImage == null, then do not allocate or create the dst image |
| but do fill out the other fields in dstMask. |
| If you do allocate a dst image, use SkMask::AllocImage() |
| If this returns false, dst mask is ignored. |
| @param dst the result of the filter. If src.fImage == null, dst should not allocate its image |
| @param src the original image to be filtered. |
| @param matrix the CTM |
| @param margin if not null, return the buffer dx/dy need when calculating the effect. Used when |
| drawing a clipped object to know how much larger to allocate the src before |
| applying the filter. If returning false, ignore this parameter. |
| @return true if the dst mask was correctly created. |
| */ |
| virtual bool filterMask(SkMask* dst, const SkMask& src, const SkMatrix&, |
| SkIPoint* margin) const; |
| |
| #if SK_SUPPORT_GPU |
| /** |
| * Returns a processor if the filter can be expressed a single-pass GrProcessor without |
| * requiring an explicit input mask. Per-pixel, the effect receives the incoming mask's |
| * coverage as the input color and outputs the filtered covereage value. This means that each |
| * pixel's filtered coverage must only depend on the unfiltered mask value for that pixel and |
| * not on surrounding values. |
| */ |
| std::unique_ptr<GrFragmentProcessor> asFragmentProcessor(const GrFPArgs& args) const; |
| |
| /** |
| * Returns true iff asFragmentProcessor() will return a processor |
| */ |
| bool hasFragmentProcessor() const; |
| |
| /** |
| * If asFragmentProcessor() fails the filter may be implemented on the GPU by a subclass |
| * overriding filterMaskGPU (declared below). That code path requires constructing a |
| * src mask as input. Since that is a potentially expensive operation, the subclass must also |
| * override this function to indicate whether filterTextureMaskGPU would succeeed if the mask |
| * were to be created. |
| * |
| * 'maskRect' returns the device space portion of the mask that the filter needs. The mask |
| * passed into 'filterMaskGPU' should have the same extent as 'maskRect' but be |
| * translated to the upper-left corner of the mask (i.e., (maskRect.fLeft, maskRect.fTop) |
| * appears at (0, 0) in the mask). |
| * |
| * Logically, how this works is: |
| * canFilterMaskGPU is called |
| * if (it returns true) |
| * the returned mask rect is used for quick rejecting |
| * either directFilterMaskGPU or directFilterRRectMaskGPU is then called |
| * if (neither of them handle the blur) |
| * the mask rect is used to generate the mask |
| * filterMaskGPU is called to filter the mask |
| * |
| * TODO: this should work as: |
| * if (canFilterMaskGPU(devShape, ...)) // rect, rrect, drrect, path |
| * filterMaskGPU(devShape, ...) |
| * this would hide the RRect special case and the mask generation |
| */ |
| virtual bool canFilterMaskGPU(const SkRRect& devRRect, |
| const SkIRect& clipBounds, |
| const SkMatrix& ctm, |
| SkRect* maskRect) const; |
| |
| /** |
| * Try to directly render the mask filter into the target. Returns true if drawing was |
| * successful. If false is returned then paint is unmodified. |
| */ |
| virtual bool directFilterMaskGPU(GrContext*, |
| GrRenderTargetContext* renderTargetContext, |
| GrPaint&& paint, |
| const GrClip&, |
| const SkMatrix& viewMatrix, |
| const SkStrokeRec& strokeRec, |
| const SkPath& path) const; |
| /** |
| * Try to directly render a rounded rect mask filter into the target. Returns |
| * true if drawing was successful. If false is returned then paint is unmodified. |
| */ |
| virtual bool directFilterRRectMaskGPU(GrContext*, |
| GrRenderTargetContext* renderTargetContext, |
| GrPaint&& paint, |
| const GrClip&, |
| const SkMatrix& viewMatrix, |
| const SkStrokeRec& strokeRec, |
| const SkRRect& rrect, |
| const SkRRect& devRRect) const; |
| |
| /** |
| * This function is used to implement filters that require an explicit src mask. It should only |
| * be called if canFilterMaskGPU returned true and the maskRect param should be the output from |
| * that call. |
| * Implementations are free to get the GrContext from the src texture in order to create |
| * additional textures and perform multiple passes. |
| */ |
| virtual sk_sp<GrTextureProxy> filterMaskGPU(GrContext*, |
| sk_sp<GrTextureProxy> srcProxy, |
| const SkMatrix& ctm, |
| const SkIRect& maskRect) const; |
| #endif |
| |
| /** |
| * The fast bounds function is used to enable the paint to be culled early |
| * in the drawing pipeline. This function accepts the current bounds of the |
| * paint as its src param and the filter adjust those bounds using its |
| * current mask and returns the result using the dest param. Callers are |
| * allowed to provide the same struct for both src and dest so each |
| * implementation must accomodate that behavior. |
| * |
| * The default impl calls filterMask with the src mask having no image, |
| * but subclasses may override this if they can compute the rect faster. |
| */ |
| virtual void computeFastBounds(const SkRect& src, SkRect* dest) const; |
| |
| struct BlurRec { |
| SkScalar fSigma; |
| SkBlurStyle fStyle; |
| SkBlurQuality fQuality; |
| }; |
| /** |
| * If this filter can be represented by a BlurRec, return true and (if not null) fill in the |
| * provided BlurRec parameter. If this effect cannot be represented as a BlurRec, return false |
| * and ignore the BlurRec parameter. |
| */ |
| virtual bool asABlur(BlurRec*) const; |
| |
| protected: |
| SkMaskFilterBase() {} |
| |
| #if SK_SUPPORT_GPU |
| virtual std::unique_ptr<GrFragmentProcessor> onAsFragmentProcessor(const GrFPArgs&) const; |
| virtual bool onHasFragmentProcessor() const; |
| #endif |
| |
| enum FilterReturn { |
| kFalse_FilterReturn, |
| kTrue_FilterReturn, |
| kUnimplemented_FilterReturn |
| }; |
| |
| class NinePatch : ::SkNoncopyable { |
| public: |
| NinePatch() : fCache(nullptr) { } |
| ~NinePatch(); |
| |
| SkMask fMask; // fBounds must have [0,0] in its top-left |
| SkIRect fOuterRect; // width/height must be >= fMask.fBounds' |
| SkIPoint fCenter; // identifies center row/col for stretching |
| SkCachedData* fCache; |
| }; |
| |
| /** |
| * Override if your subclass can filter a rect, and return the answer as |
| * a ninepatch mask to be stretched over the returned outerRect. On success |
| * return kTrue_FilterReturn. On failure (e.g. out of memory) return |
| * kFalse_FilterReturn. If the normal filterMask() entry-point should be |
| * called (the default) return kUnimplemented_FilterReturn. |
| * |
| * By convention, the caller will take the center rol/col from the returned |
| * mask as the slice it can replicate horizontally and vertically as we |
| * stretch the mask to fit inside outerRect. It is an error for outerRect |
| * to be smaller than the mask's bounds. This would imply that the width |
| * and height of the mask should be odd. This is not required, just that |
| * the caller will call mask.fBounds.centerX() and centerY() to find the |
| * strips that will be replicated. |
| */ |
| virtual FilterReturn filterRectsToNine(const SkRect[], int count, |
| const SkMatrix&, |
| const SkIRect& clipBounds, |
| NinePatch*) const; |
| /** |
| * Similar to filterRectsToNine, except it performs the work on a round rect. |
| */ |
| virtual FilterReturn filterRRectToNine(const SkRRect&, const SkMatrix&, |
| const SkIRect& clipBounds, |
| NinePatch*) const; |
| |
| private: |
| friend class SkDraw; |
| |
| /** Helper method that, given a path in device space, will rasterize it into a kA8_Format mask |
| and then call filterMask(). If this returns true, the specified blitter will be called |
| to render that mask. Returns false if filterMask() returned false. |
| This method is not exported to java. |
| */ |
| bool filterPath(const SkPath& devPath, const SkMatrix& ctm, const SkRasterClip&, SkBlitter*, |
| SkStrokeRec::InitStyle) const; |
| |
| /** Helper method that, given a roundRect in device space, will rasterize it into a kA8_Format |
| mask and then call filterMask(). If this returns true, the specified blitter will be called |
| to render that mask. Returns false if filterMask() returned false. |
| */ |
| bool filterRRect(const SkRRect& devRRect, const SkMatrix& ctm, const SkRasterClip&, |
| SkBlitter*) const; |
| |
| typedef SkFlattenable INHERITED; |
| }; |
| |
| inline SkMaskFilterBase* as_MFB(SkMaskFilter* mf) { |
| return static_cast<SkMaskFilterBase*>(mf); |
| } |
| |
| inline const SkMaskFilterBase* as_MFB(const SkMaskFilter* mf) { |
| return static_cast<const SkMaskFilterBase*>(mf); |
| } |
| |
| inline const SkMaskFilterBase* as_MFB(const sk_sp<SkMaskFilter>& mf) { |
| return static_cast<SkMaskFilterBase*>(mf.get()); |
| } |
| |
| #endif |